// ==UserScript==
// @name         amobbs 论坛链接播放按钮
// @namespace    https://www.amobbs.com/
// @version      1.0.0
// @description  在 amobbs.com 帖子页面中，为哔哩哔哩视频链接(b23.tv / bilibili.com)后面添加播放按钮，点击后弹窗播放
// @author       you
// @match        https://www.amobbs.com/*
// @match        https://amobbs.com/*
// @grant        GM_xmlhttpRequest
// @grant        GM_setValue
// @grant        GM_getValue
// @connect      b23.tv
// @connect      api.bilibili.com
// @connect      bilibili.com
// @connect      www.bilibili.com
// @run-at       document-idle
// @license MIT
// ==/UserScript==

(function () {
  'use strict';

  var LINK_RE = /^(https?:\/\/)?((www\.)?bilibili\.com\/video\/(BV[0-9A-Za-z]+|av\d+)|b23\.tv\/[0-9A-Za-z]+)/i;
  var POPUP_ID = 'tm-video-popup';

  function extractPlayId(url) {
    var m;
    m = url.match(/bilibili\.com\/video\/(BV[0-9A-Za-z]+)/i);
    if (m) return { bvid: m[1] };
    m = url.match(/bilibili\.com\/video\/av(\d+)/i);
    if (m) return { aid: m[1] };
    m = url.match(/b23\.tv\/([0-9A-Za-z]+)/i);
    if (m) return { short: m[1] };
    return null;
  }

  function buildEmbedUrl(id) {
    if (id.bvid) {
      return 'https://player.bilibili.com/player.html?bvid=' + id.bvid + '&page=1&high_quality=1&danmaku=0';
    }
    if (id.aid) {
      return 'https://player.bilibili.com/player.html?aid=' + id.aid + '&page=1&high_quality=1&danmaku=0';
    }
    return null;
  }

  function resolveShort(code) {
    var cacheKey = 'b23_' + code;
    var cached = GM_getValue(cacheKey, null);
    if (cached) return Promise.resolve(cached);

    return new Promise(function (resolve, reject) {
      GM_xmlhttpRequest({
        method: 'GET',
        url: 'https://b23.tv/' + code,
        redirect: 'follow',
        timeout: 15000,
        onload: function (resp) {
          var finalUrl = (resp.finalUrl && resp.finalUrl !== '') ? resp.finalUrl : '';
          if (!finalUrl) {
            var m = resp.responseText && resp.responseText.match(/url\s*=\s*["']([^"']+)["']/i);
            if (m) finalUrl = m[1];
          }
          var id = extractPlayId(finalUrl);
          if (id && (id.bvid || id.aid)) {
            GM_setValue(cacheKey, id);
            resolve(id);
          } else {
            reject(new Error('短链接解析失败'));
          }
        },
        onerror: function (e) { reject(new Error('短链接请求失败：' + ((e && e.error) ? e.error : '网络错误'))); },
        ontimeout: function () { reject(new Error('短链接请求超时')); }
      });
    });
  }

  function getOrCreatePopup() {
    var popup = document.getElementById(POPUP_ID);
    if (popup) return popup;

    var overlay = document.createElement('div');
    overlay.id = POPUP_ID;
    overlay.style.cssText = [
      'position:fixed', 'left:0', 'top:0', 'width:100%', 'height:100%',
      'background:rgba(0,0,0,0.65)', 'z-index:2147483000',
      'display:none', 'align-items:center', 'justify-content:center'
    ].join(';');

    var box = document.createElement('div');
    box.style.cssText = [
      'position:relative', 'width:min(860px,92vw)', 'background:#0b0b0f',
      'border-radius:10px', 'box-shadow:0 12px 48px rgba(0,0,0,0.7)',
      'overflow:hidden', 'display:flex', 'flex-direction:column'
    ].join(';');

    var bar = document.createElement('div');
    bar.style.cssText = 'display:flex;align-items:center;justify-content:space-between;padding:10px 14px;background:#18181c;color:#eee;font-size:14px;cursor:move;';
    var title = document.createElement('span');
    title.textContent = '视频播放';
    title.style.cssText = 'white-space:nowrap;overflow:hidden;text-overflow:ellipsis;';
    var close = document.createElement('span');
    close.textContent = '✕';
    close.title = '关闭 (Esc)';
    close.style.cssText = 'cursor:pointer;padding:2px 8px;border-radius:6px;background:#333;font-size:16px;line-height:22px;';
    close.addEventListener('mouseenter', function () { close.style.background = '#e33'; });
    close.addEventListener('mouseleave', function () { close.style.background = '#333'; });
    close.addEventListener('click', hidePopup);
    bar.appendChild(title);
    bar.appendChild(close);

    var body = document.createElement('div');
    body.style.cssText = 'position:relative;aspect-ratio:16/9;background:#000;';
    var msg = document.createElement('div');
    msg.style.cssText = 'position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:#ccc;font-size:14px;';
    msg.textContent = '解析视频链接中…';
    body.appendChild(msg);

    box.appendChild(bar);
    box.appendChild(body);
    overlay.appendChild(box);

    box._title = title;
    box._body = body;
    box._msg = msg;
    overlay._box = box;

    document.documentElement.appendChild(overlay);
    return overlay;
  }

  function showPopup(url) {
    var overlay = getOrCreatePopup();
    var box = overlay._box;
    overlay.style.display = 'flex';
    box._body.querySelectorAll('iframe').forEach(function (f) { f.remove(); });
    box._msg.style.display = 'flex';
    box._msg.textContent = '解析视频链接中…';

    var id = extractPlayId(url);
    var promise;
    if (id && id.short) {
      promise = resolveShort(id.short);
    } else if (id && (id.bvid || id.aid)) {
      promise = Promise.resolve(id);
    } else {
      promise = Promise.reject(new Error('无法识别的视频链接'));
    }

    promise.then(function (resolved) {
      var embedUrl = buildEmbedUrl(resolved);
      if (!embedUrl) throw new Error('无法生成播放地址');
      var iframe = document.createElement('iframe');
      iframe.src = embedUrl;
      iframe.setAttribute('scrolling', 'no');
      iframe.setAttribute('frameborder', '0');
      iframe.setAttribute('allowfullscreen', 'true');
      iframe.setAttribute('allow', 'autoplay; fullscreen');
      iframe.style.cssText = 'position:absolute;inset:0;width:100%;height:100%;border:0;';
      box._msg.style.display = 'none';
      box._body.appendChild(iframe);
    }).catch(function (err) {
      box._msg.style.display = 'flex';
      box._msg.innerHTML = '';
      var line = document.createElement('div');
      line.style.cssText = 'text-align:center;';
      line.textContent = '播放失败：' + err.message;
      var openLink = document.createElement('a');
      openLink.href = url;
      openLink.target = '_blank';
      openLink.rel = 'noopener';
      openLink.textContent = ' 在新窗口打开链接';
      openLink.style.cssText = 'display:inline-block;margin-top:8px;color:#5ad;';
      line.appendChild(openLink);
      box._msg.appendChild(line);
    });
  }

  function hidePopup() {
    var overlay = document.getElementById(POPUP_ID);
    if (!overlay) return;
    overlay.style.display = 'none';
    var box = overlay._box;
    if (box) {
      box._body.querySelectorAll('iframe').forEach(function (f) { f.remove(); });
    }
  }

  function makePlayButton(url) {
    var btn = document.createElement('button');
    btn.type = 'button';
    btn.textContent = '▶ 播放';
    btn.title = '弹窗播放：' + url;
    btn.style.cssText = [
      'display:inline-block', 'margin:0 4px', 'padding:2px 10px',
      'background:#fb7299', 'color:#fff', 'border:0', 'border-radius:6px',
      'font-size:12px', 'line-height:18px', 'cursor:pointer',
      'vertical-align:middle', 'box-shadow:0 1px 3px rgba(0,0,0,0.25)'
    ].join(';');
    btn.addEventListener('mouseenter', function () { btn.style.background = '#ff85a8'; });
    btn.addEventListener('mouseleave', function () { btn.style.background = '#fb7299'; });
    btn.addEventListener('click', function (e) {
      e.preventDefault();
      e.stopPropagation();
      showPopup(url);
    });
    return btn;
  }

  function attachButtons() {
    document.querySelectorAll('a[href]').forEach(function (a) {
      if (a.dataset.tmPlayBtn === '1') return;
      var href = a.href || '';
      if (!LINK_RE.test(href)) return;
      a.dataset.tmPlayBtn = '1';
      a.insertAdjacentElement('afterend', makePlayButton(href));
    });
  }

  document.addEventListener('keydown', function (e) {
    if (e.key === 'Escape') {
      var overlay = document.getElementById(POPUP_ID);
      if (overlay && overlay.style.display === 'flex') hidePopup();
    }
  });

  window.addEventListener('click', function (e) {
    var overlay = document.getElementById(POPUP_ID);
    if (overlay && e.target === overlay) hidePopup();
  });

  document.addEventListener('dragstart', function (e) {
    var overlay = document.getElementById(POPUP_ID);
    if (!overlay || overlay.style.display !== 'flex') return;
    var box = overlay._box;
    var bar = box.querySelector('div');
    if (!bar || !bar.contains(e.target)) return;
    var shiftX = e.clientX - box.getBoundingClientRect().left;
    var shiftY = e.clientY - box.getBoundingClientRect().top;
    function move(ev) {
      var x = ev.clientX - shiftX;
      var y = ev.clientY - shiftY;
      overlay.style.alignItems = 'flex-start';
      overlay.style.justifyContent = 'flex-start';
      box.style.marginLeft = Math.max(0, x) + 'px';
      box.style.marginTop = Math.max(0, y) + 'px';
    }
    function up() {
      document.removeEventListener('mousemove', move);
      document.removeEventListener('mouseup', up);
    }
    document.addEventListener('mousemove', move);
    document.addEventListener('mouseup', up);
  });

  attachButtons();

  var observerStarted = false;
  function startObserver() {
    var root = document.body || document.documentElement;
    if (!root) {
      document.addEventListener('DOMContentLoaded', startObserver, { once: true });
      return;
    }
    if (observerStarted) return;
    observerStarted = true;
    new MutationObserver(function () {
      attachButtons();
    }).observe(root, { childList: true, subtree: true });
  }
  startObserver();
})();